The test wetlands were created in 1994 and fed with water pumped from the Olentangy River to mimic natural conditions. The difference was that one was consciously planted with 13 varietals of marsh plant and one was left bare and built up its plant life from seeds floating in the air and water or attached to animals migrating through.

Fifteen years later, both marshes had the same plant diversity and abundance. The only difference being the unplanted one captured more carbon along the way.